Printing: Add ability to get the default printer from the print backend.

BUG=84126
TEST=none

Review URL: http://codereview.chromium.org/7087011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@87187 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 25 insertions, 9 deletions

diff --git a/printing/backend/print_backend.h b/printing/backend/print_backend.h
index a6caa51..f53eaa5 100644
--- a/printing/backend/print_backend.h
+++ b/printing/backend/print_backend.h
@@ -54,6 +54,9 @@ class PrintBackend : public base::RefCountedThreadSafe<PrintBackend> {
   // Enumerates the list of installed local and network printers.
   virtual bool EnumeratePrinters(PrinterList* printer_list) = 0;
 
+  // Get the default printer name. Empty string if no default printer.
+  virtual std::string GetDefaultPrinterName() = 0;
+
   // Gets the capabilities and defaults for a specific printer.
   virtual bool GetPrinterCapsAndDefaults(
       const std::string& printer_name,
diff --git a/printing/backend/print_backend_cups.cc b/printing/backend/print_backend_cups.cc
index 2e63145..9b6976c 100644
--- a/printing/backend/print_backend_cups.cc
+++ b/printing/backend/print_backend_cups.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -86,6 +86,8 @@ class PrintBackendCUPS : public PrintBackend {
   // PrintBackend implementation.
   virtual bool EnumeratePrinters(PrinterList* printer_list);
 
+  virtual std::string GetDefaultPrinterName();
+
   virtual bool GetPrinterCapsAndDefaults(const std::string& printer_name,
                                          PrinterCapsAndDefaults* printer_info);
 
@@ -153,6 +155,13 @@ bool PrintBackendCUPS::EnumeratePrinters(PrinterList* printer_list) {
   return true;
 }
 
+std::string PrintBackendCUPS::GetDefaultPrinterName() {
+  // TODO(thestig) Figure out why cupsGetDefault() lies about the default
+  // printer. :-(
+  // Return an empty string for now.
+  return std::string();
+}
+
 bool PrintBackendCUPS::GetPrinterCapsAndDefaults(
     const std::string& printer_name,
     PrinterCapsAndDefaults* printer_info) {
diff --git a/printing/backend/print_backend_win.cc b/printing/backend/print_backend_win.cc
index d482a91..3fb0573 100644
--- a/printing/backend/print_backend_win.cc
+++ b/printing/backend/print_backend_win.cc
@@ -42,6 +42,8 @@ class PrintBackendWin : public PrintBackend {
 
   virtual bool EnumeratePrinters(PrinterList* printer_list);
 
+  virtual std::string GetDefaultPrinterName();
+
   virtual bool GetPrinterCapsAndDefaults(const std::string& printer_name,
                                          PrinterCapsAndDefaults* printer_info);
 
@@ -64,19 +66,13 @@ bool PrintBackendWin::EnumeratePrinters(PrinterList* printer_list) {
   if (!ret)
     return false;
 
-  // Getting the name of the default printer.
-  DWORD size = MAX_PATH;
-  TCHAR default_printer_name[MAX_PATH];
-  BOOL default_printer_exists = ::GetDefaultPrinter(
-      default_printer_name, &size);
-
+  std::string default_printer = GetDefaultPrinterName();
   PRINTER_INFO_2* printer_info =
       reinterpret_cast<PRINTER_INFO_2*>(printer_info_buffer.get());
   for (DWORD index = 0; index < count_returned; index++) {
     PrinterBasicInfo info;
     info.printer_name = WideToUTF8(printer_info[index].pPrinterName);
-    if (default_printer_exists)
-      info.is_default = (info.printer_name == WideToUTF8(default_printer_name));
+    info.is_default = (info.printer_name == default_printer);
     if (printer_info[index].pComment)
       info.printer_description = WideToUTF8(printer_info[index].pComment);
     info.printer_status = printer_info[index].Status;
@@ -91,6 +87,14 @@ bool PrintBackendWin::EnumeratePrinters(PrinterList* printer_list) {
   return true;
 }
 
+std::string PrintBackendWin::GetDefaultPrinterName() {
+  DWORD size = MAX_PATH;
+  TCHAR default_printer_name[MAX_PATH];
+  if (!::GetDefaultPrinter(default_printer_name, &size))
+    return std::string();
+  return WideToUTF8(default_printer_name);
+}
+
 bool PrintBackendWin::GetPrinterCapsAndDefaults(
     const std::string& printer_name,
     PrinterCapsAndDefaults* printer_info) {